]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - kernel/power/snapshot.c
2 * linux/kernel/power/snapshot.c
4 * This file provides system snapshot/restore functionality for swsusp.
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * This file is released under the GPLv2.
13 #include <linux/version.h>
14 #include <linux/module.h>
16 #include <linux/suspend.h>
17 #include <linux/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/spinlock.h>
20 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/bootmem.h>
25 #include <linux/syscalls.h>
26 #include <linux/console.h>
27 #include <linux/highmem.h>
29 #include <asm/uaccess.h>
30 #include <asm/mmu_context.h>
31 #include <asm/pgtable.h>
32 #include <asm/tlbflush.h>
37 static int swsusp_page_is_free(struct page
*);
38 static void swsusp_set_page_forbidden(struct page
*);
39 static void swsusp_unset_page_forbidden(struct page
*);
41 /* List of PBEs needed for restoring the pages that were allocated before
42 * the suspend and included in the suspend image, but have also been
43 * allocated by the "resume" kernel, so their contents cannot be written
44 * directly to their "original" page frames.
46 struct pbe
*restore_pblist
;
48 /* Pointer to an auxiliary buffer (1 page) */
52 * @safe_needed - on resume, for storing the PBE list and the image,
53 * we can only use memory pages that do not conflict with the pages
54 * used before suspend. The unsafe pages have PageNosaveFree set
55 * and we count them using unsafe_pages.
57 * Each allocated image page is marked as PageNosave and PageNosaveFree
58 * so that swsusp_free() can release it.
63 #define PG_UNSAFE_CLEAR 1
64 #define PG_UNSAFE_KEEP 0
66 static unsigned int allocated_unsafe_pages
;
68 static void *get_image_page(gfp_t gfp_mask
, int safe_needed
)
72 res
= (void *)get_zeroed_page(gfp_mask
);
74 while (res
&& swsusp_page_is_free(virt_to_page(res
))) {
75 /* The page is unsafe, mark it for swsusp_free() */
76 swsusp_set_page_forbidden(virt_to_page(res
));
77 allocated_unsafe_pages
++;
78 res
= (void *)get_zeroed_page(gfp_mask
);
81 swsusp_set_page_forbidden(virt_to_page(res
));
82 swsusp_set_page_free(virt_to_page(res
));
87 unsigned long get_safe_page(gfp_t gfp_mask
)
89 return (unsigned long)get_image_page(gfp_mask
, PG_SAFE
);
92 static struct page
*alloc_image_page(gfp_t gfp_mask
)
96 page
= alloc_page(gfp_mask
);
98 swsusp_set_page_forbidden(page
);
99 swsusp_set_page_free(page
);
105 * free_image_page - free page represented by @addr, allocated with
106 * get_image_page (page flags set by it must be cleared)
109 static inline void free_image_page(void *addr
, int clear_nosave_free
)
113 BUG_ON(!virt_addr_valid(addr
));
115 page
= virt_to_page(addr
);
117 swsusp_unset_page_forbidden(page
);
118 if (clear_nosave_free
)
119 swsusp_unset_page_free(page
);
124 /* struct linked_page is used to build chains of pages */
126 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
129 struct linked_page
*next
;
130 char data
[LINKED_PAGE_DATA_SIZE
];
131 } __attribute__((packed
));
134 free_list_of_pages(struct linked_page
*list
, int clear_page_nosave
)
137 struct linked_page
*lp
= list
->next
;
139 free_image_page(list
, clear_page_nosave
);
145 * struct chain_allocator is used for allocating small objects out of
146 * a linked list of pages called 'the chain'.
148 * The chain grows each time when there is no room for a new object in
149 * the current page. The allocated objects cannot be freed individually.
150 * It is only possible to free them all at once, by freeing the entire
153 * NOTE: The chain allocator may be inefficient if the allocated objects
154 * are not much smaller than PAGE_SIZE.
157 struct chain_allocator
{
158 struct linked_page
*chain
; /* the chain */
159 unsigned int used_space
; /* total size of objects allocated out
160 * of the current page
162 gfp_t gfp_mask
; /* mask for allocating pages */
163 int safe_needed
; /* if set, only "safe" pages are allocated */
167 chain_init(struct chain_allocator
*ca
, gfp_t gfp_mask
, int safe_needed
)
170 ca
->used_space
= LINKED_PAGE_DATA_SIZE
;
171 ca
->gfp_mask
= gfp_mask
;
172 ca
->safe_needed
= safe_needed
;
175 static void *chain_alloc(struct chain_allocator
*ca
, unsigned int size
)
179 if (LINKED_PAGE_DATA_SIZE
- ca
->used_space
< size
) {
180 struct linked_page
*lp
;
182 lp
= get_image_page(ca
->gfp_mask
, ca
->safe_needed
);
186 lp
->next
= ca
->chain
;
190 ret
= ca
->chain
->data
+ ca
->used_space
;
191 ca
->used_space
+= size
;
195 static void chain_free(struct chain_allocator
*ca
, int clear_page_nosave
)
197 free_list_of_pages(ca
->chain
, clear_page_nosave
);
198 memset(ca
, 0, sizeof(struct chain_allocator
));
202 * Data types related to memory bitmaps.
204 * Memory bitmap is a structure consiting of many linked lists of
205 * objects. The main list's elements are of type struct zone_bitmap
206 * and each of them corresonds to one zone. For each zone bitmap
207 * object there is a list of objects of type struct bm_block that
208 * represent each blocks of bit chunks in which information is
211 * struct memory_bitmap contains a pointer to the main list of zone
212 * bitmap objects, a struct bm_position used for browsing the bitmap,
213 * and a pointer to the list of pages used for allocating all of the
214 * zone bitmap objects and bitmap block objects.
216 * NOTE: It has to be possible to lay out the bitmap in memory
217 * using only allocations of order 0. Additionally, the bitmap is
218 * designed to work with arbitrary number of zones (this is over the
219 * top for now, but let's avoid making unnecessary assumptions ;-).
221 * struct zone_bitmap contains a pointer to a list of bitmap block
222 * objects and a pointer to the bitmap block object that has been
223 * most recently used for setting bits. Additionally, it contains the
224 * pfns that correspond to the start and end of the represented zone.
226 * struct bm_block contains a pointer to the memory page in which
227 * information is stored (in the form of a block of bit chunks
228 * of type unsigned long each). It also contains the pfns that
229 * correspond to the start and end of the represented memory area and
230 * the number of bit chunks in the block.
233 #define BM_END_OF_MAP (~0UL)
235 #define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long))
236 #define BM_BITS_PER_CHUNK (sizeof(long) << 3)
237 #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3)
240 struct bm_block
*next
; /* next element of the list */
241 unsigned long start_pfn
; /* pfn represented by the first bit */
242 unsigned long end_pfn
; /* pfn represented by the last bit plus 1 */
243 unsigned int size
; /* number of bit chunks */
244 unsigned long *data
; /* chunks of bits representing pages */
248 struct zone_bitmap
*next
; /* next element of the list */
249 unsigned long start_pfn
; /* minimal pfn in this zone */
250 unsigned long end_pfn
; /* maximal pfn in this zone plus 1 */
251 struct bm_block
*bm_blocks
; /* list of bitmap blocks */
252 struct bm_block
*cur_block
; /* recently used bitmap block */
255 /* strcut bm_position is used for browsing memory bitmaps */
258 struct zone_bitmap
*zone_bm
;
259 struct bm_block
*block
;
264 struct memory_bitmap
{
265 struct zone_bitmap
*zone_bm_list
; /* list of zone bitmaps */
266 struct linked_page
*p_list
; /* list of pages used to store zone
267 * bitmap objects and bitmap block
270 struct bm_position cur
; /* most recently used bit position */
273 /* Functions that operate on memory bitmaps */
275 static inline void memory_bm_reset_chunk(struct memory_bitmap
*bm
)
281 static void memory_bm_position_reset(struct memory_bitmap
*bm
)
283 struct zone_bitmap
*zone_bm
;
285 zone_bm
= bm
->zone_bm_list
;
286 bm
->cur
.zone_bm
= zone_bm
;
287 bm
->cur
.block
= zone_bm
->bm_blocks
;
288 memory_bm_reset_chunk(bm
);
291 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
);
294 * create_bm_block_list - create a list of block bitmap objects
297 static inline struct bm_block
*
298 create_bm_block_list(unsigned int nr_blocks
, struct chain_allocator
*ca
)
300 struct bm_block
*bblist
= NULL
;
302 while (nr_blocks
-- > 0) {
305 bb
= chain_alloc(ca
, sizeof(struct bm_block
));
316 * create_zone_bm_list - create a list of zone bitmap objects
319 static inline struct zone_bitmap
*
320 create_zone_bm_list(unsigned int nr_zones
, struct chain_allocator
*ca
)
322 struct zone_bitmap
*zbmlist
= NULL
;
324 while (nr_zones
-- > 0) {
325 struct zone_bitmap
*zbm
;
327 zbm
= chain_alloc(ca
, sizeof(struct zone_bitmap
));
338 * memory_bm_create - allocate memory for a memory bitmap
342 memory_bm_create(struct memory_bitmap
*bm
, gfp_t gfp_mask
, int safe_needed
)
344 struct chain_allocator ca
;
346 struct zone_bitmap
*zone_bm
;
350 chain_init(&ca
, gfp_mask
, safe_needed
);
352 /* Compute the number of zones */
355 if (populated_zone(zone
))
358 /* Allocate the list of zones bitmap objects */
359 zone_bm
= create_zone_bm_list(nr
, &ca
);
360 bm
->zone_bm_list
= zone_bm
;
362 chain_free(&ca
, PG_UNSAFE_CLEAR
);
366 /* Initialize the zone bitmap objects */
367 for_each_zone(zone
) {
370 if (!populated_zone(zone
))
373 zone_bm
->start_pfn
= zone
->zone_start_pfn
;
374 zone_bm
->end_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
375 /* Allocate the list of bitmap block objects */
376 nr
= DIV_ROUND_UP(zone
->spanned_pages
, BM_BITS_PER_BLOCK
);
377 bb
= create_bm_block_list(nr
, &ca
);
378 zone_bm
->bm_blocks
= bb
;
379 zone_bm
->cur_block
= bb
;
383 nr
= zone
->spanned_pages
;
384 pfn
= zone
->zone_start_pfn
;
385 /* Initialize the bitmap block objects */
389 ptr
= get_image_page(gfp_mask
, safe_needed
);
395 if (nr
>= BM_BITS_PER_BLOCK
) {
396 pfn
+= BM_BITS_PER_BLOCK
;
397 bb
->size
= BM_CHUNKS_PER_BLOCK
;
398 nr
-= BM_BITS_PER_BLOCK
;
400 /* This is executed only once in the loop */
402 bb
->size
= DIV_ROUND_UP(nr
, BM_BITS_PER_CHUNK
);
407 zone_bm
= zone_bm
->next
;
409 bm
->p_list
= ca
.chain
;
410 memory_bm_position_reset(bm
);
414 bm
->p_list
= ca
.chain
;
415 memory_bm_free(bm
, PG_UNSAFE_CLEAR
);
420 * memory_bm_free - free memory occupied by the memory bitmap @bm
423 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
)
425 struct zone_bitmap
*zone_bm
;
427 /* Free the list of bit blocks for each zone_bitmap object */
428 zone_bm
= bm
->zone_bm_list
;
432 bb
= zone_bm
->bm_blocks
;
435 free_image_page(bb
->data
, clear_nosave_free
);
438 zone_bm
= zone_bm
->next
;
440 free_list_of_pages(bm
->p_list
, clear_nosave_free
);
441 bm
->zone_bm_list
= NULL
;
445 * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
446 * to given pfn. The cur_zone_bm member of @bm and the cur_block member
447 * of @bm->cur_zone_bm are updated.
450 static void memory_bm_find_bit(struct memory_bitmap
*bm
, unsigned long pfn
,
451 void **addr
, unsigned int *bit_nr
)
453 struct zone_bitmap
*zone_bm
;
456 /* Check if the pfn is from the current zone */
457 zone_bm
= bm
->cur
.zone_bm
;
458 if (pfn
< zone_bm
->start_pfn
|| pfn
>= zone_bm
->end_pfn
) {
459 zone_bm
= bm
->zone_bm_list
;
460 /* We don't assume that the zones are sorted by pfns */
461 while (pfn
< zone_bm
->start_pfn
|| pfn
>= zone_bm
->end_pfn
) {
462 zone_bm
= zone_bm
->next
;
466 bm
->cur
.zone_bm
= zone_bm
;
468 /* Check if the pfn corresponds to the current bitmap block */
469 bb
= zone_bm
->cur_block
;
470 if (pfn
< bb
->start_pfn
)
471 bb
= zone_bm
->bm_blocks
;
473 while (pfn
>= bb
->end_pfn
) {
478 zone_bm
->cur_block
= bb
;
479 pfn
-= bb
->start_pfn
;
480 *bit_nr
= pfn
% BM_BITS_PER_CHUNK
;
481 *addr
= bb
->data
+ pfn
/ BM_BITS_PER_CHUNK
;
484 static void memory_bm_set_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
489 memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
493 static void memory_bm_clear_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
498 memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
499 clear_bit(bit
, addr
);
502 static int memory_bm_test_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
507 memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
508 return test_bit(bit
, addr
);
511 /* Two auxiliary functions for memory_bm_next_pfn */
513 /* Find the first set bit in the given chunk, if there is one */
515 static inline int next_bit_in_chunk(int bit
, unsigned long *chunk_p
)
518 while (bit
< BM_BITS_PER_CHUNK
) {
519 if (test_bit(bit
, chunk_p
))
527 /* Find a chunk containing some bits set in given block of bits */
529 static inline int next_chunk_in_block(int n
, struct bm_block
*bb
)
532 while (n
< bb
->size
) {
542 * memory_bm_next_pfn - find the pfn that corresponds to the next set bit
543 * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
546 * It is required to run memory_bm_position_reset() before the first call to
550 static unsigned long memory_bm_next_pfn(struct memory_bitmap
*bm
)
552 struct zone_bitmap
*zone_bm
;
560 chunk
= bm
->cur
.chunk
;
563 bit
= next_bit_in_chunk(bit
, bb
->data
+ chunk
);
567 chunk
= next_chunk_in_block(chunk
, bb
);
569 } while (chunk
>= 0);
572 memory_bm_reset_chunk(bm
);
574 zone_bm
= bm
->cur
.zone_bm
->next
;
576 bm
->cur
.zone_bm
= zone_bm
;
577 bm
->cur
.block
= zone_bm
->bm_blocks
;
578 memory_bm_reset_chunk(bm
);
581 memory_bm_position_reset(bm
);
582 return BM_END_OF_MAP
;
585 bm
->cur
.chunk
= chunk
;
587 return bb
->start_pfn
+ chunk
* BM_BITS_PER_CHUNK
+ bit
;
591 * This structure represents a range of page frames the contents of which
592 * should not be saved during the suspend.
595 struct nosave_region
{
596 struct list_head list
;
597 unsigned long start_pfn
;
598 unsigned long end_pfn
;
601 static LIST_HEAD(nosave_regions
);
604 * register_nosave_region - register a range of page frames the contents
605 * of which should not be saved during the suspend (to be used in the early
606 * initialization code)
610 __register_nosave_region(unsigned long start_pfn
, unsigned long end_pfn
,
613 struct nosave_region
*region
;
615 if (start_pfn
>= end_pfn
)
618 if (!list_empty(&nosave_regions
)) {
619 /* Try to extend the previous region (they should be sorted) */
620 region
= list_entry(nosave_regions
.prev
,
621 struct nosave_region
, list
);
622 if (region
->end_pfn
== start_pfn
) {
623 region
->end_pfn
= end_pfn
;
628 /* during init, this shouldn't fail */
629 region
= kmalloc(sizeof(struct nosave_region
), GFP_KERNEL
);
632 /* This allocation cannot fail */
633 region
= alloc_bootmem_low(sizeof(struct nosave_region
));
634 region
->start_pfn
= start_pfn
;
635 region
->end_pfn
= end_pfn
;
636 list_add_tail(®ion
->list
, &nosave_regions
);
638 printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
639 start_pfn
<< PAGE_SHIFT
, end_pfn
<< PAGE_SHIFT
);
643 * Set bits in this map correspond to the page frames the contents of which
644 * should not be saved during the suspend.
646 static struct memory_bitmap
*forbidden_pages_map
;
648 /* Set bits in this map correspond to free page frames. */
649 static struct memory_bitmap
*free_pages_map
;
652 * Each page frame allocated for creating the image is marked by setting the
653 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
656 void swsusp_set_page_free(struct page
*page
)
659 memory_bm_set_bit(free_pages_map
, page_to_pfn(page
));
662 static int swsusp_page_is_free(struct page
*page
)
664 return free_pages_map
?
665 memory_bm_test_bit(free_pages_map
, page_to_pfn(page
)) : 0;
668 void swsusp_unset_page_free(struct page
*page
)
671 memory_bm_clear_bit(free_pages_map
, page_to_pfn(page
));
674 static void swsusp_set_page_forbidden(struct page
*page
)
676 if (forbidden_pages_map
)
677 memory_bm_set_bit(forbidden_pages_map
, page_to_pfn(page
));
680 int swsusp_page_is_forbidden(struct page
*page
)
682 return forbidden_pages_map
?
683 memory_bm_test_bit(forbidden_pages_map
, page_to_pfn(page
)) : 0;
686 static void swsusp_unset_page_forbidden(struct page
*page
)
688 if (forbidden_pages_map
)
689 memory_bm_clear_bit(forbidden_pages_map
, page_to_pfn(page
));
693 * mark_nosave_pages - set bits corresponding to the page frames the
694 * contents of which should not be saved in a given bitmap.
697 static void mark_nosave_pages(struct memory_bitmap
*bm
)
699 struct nosave_region
*region
;
701 if (list_empty(&nosave_regions
))
704 list_for_each_entry(region
, &nosave_regions
, list
) {
707 printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
708 region
->start_pfn
<< PAGE_SHIFT
,
709 region
->end_pfn
<< PAGE_SHIFT
);
711 for (pfn
= region
->start_pfn
; pfn
< region
->end_pfn
; pfn
++)
713 memory_bm_set_bit(bm
, pfn
);
718 * create_basic_memory_bitmaps - create bitmaps needed for marking page
719 * frames that should not be saved and free page frames. The pointers
720 * forbidden_pages_map and free_pages_map are only modified if everything
721 * goes well, because we don't want the bits to be used before both bitmaps
725 int create_basic_memory_bitmaps(void)
727 struct memory_bitmap
*bm1
, *bm2
;
730 BUG_ON(forbidden_pages_map
|| free_pages_map
);
732 bm1
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
736 error
= memory_bm_create(bm1
, GFP_KERNEL
, PG_ANY
);
738 goto Free_first_object
;
740 bm2
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
742 goto Free_first_bitmap
;
744 error
= memory_bm_create(bm2
, GFP_KERNEL
, PG_ANY
);
746 goto Free_second_object
;
748 forbidden_pages_map
= bm1
;
749 free_pages_map
= bm2
;
750 mark_nosave_pages(forbidden_pages_map
);
752 printk("swsusp: Basic memory bitmaps created\n");
759 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
766 * free_basic_memory_bitmaps - free memory bitmaps allocated by
767 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
768 * so that the bitmaps themselves are not referred to while they are being
772 void free_basic_memory_bitmaps(void)
774 struct memory_bitmap
*bm1
, *bm2
;
776 BUG_ON(!(forbidden_pages_map
&& free_pages_map
));
778 bm1
= forbidden_pages_map
;
779 bm2
= free_pages_map
;
780 forbidden_pages_map
= NULL
;
781 free_pages_map
= NULL
;
782 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
784 memory_bm_free(bm2
, PG_UNSAFE_CLEAR
);
787 printk("swsusp: Basic memory bitmaps freed\n");
791 * snapshot_additional_pages - estimate the number of additional pages
792 * be needed for setting up the suspend image data structures for given
793 * zone (usually the returned value is greater than the exact number)
796 unsigned int snapshot_additional_pages(struct zone
*zone
)
800 res
= DIV_ROUND_UP(zone
->spanned_pages
, BM_BITS_PER_BLOCK
);
801 res
+= DIV_ROUND_UP(res
* sizeof(struct bm_block
), PAGE_SIZE
);
805 #ifdef CONFIG_HIGHMEM
807 * count_free_highmem_pages - compute the total number of free highmem
808 * pages, system-wide.
811 static unsigned int count_free_highmem_pages(void)
814 unsigned int cnt
= 0;
817 if (populated_zone(zone
) && is_highmem(zone
))
818 cnt
+= zone_page_state(zone
, NR_FREE_PAGES
);
824 * saveable_highmem_page - Determine whether a highmem page should be
825 * included in the suspend image.
827 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
828 * and it isn't a part of a free chunk of pages.
831 static struct page
*saveable_highmem_page(unsigned long pfn
)
838 page
= pfn_to_page(pfn
);
840 BUG_ON(!PageHighMem(page
));
842 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
) ||
850 * count_highmem_pages - compute the total number of saveable highmem
854 unsigned int count_highmem_pages(void)
859 for_each_zone(zone
) {
860 unsigned long pfn
, max_zone_pfn
;
862 if (!is_highmem(zone
))
865 mark_free_pages(zone
);
866 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
867 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
868 if (saveable_highmem_page(pfn
))
874 static inline void *saveable_highmem_page(unsigned long pfn
) { return NULL
; }
875 static inline unsigned int count_highmem_pages(void) { return 0; }
876 #endif /* CONFIG_HIGHMEM */
879 * saveable - Determine whether a non-highmem page should be included in
882 * We should save the page if it isn't Nosave, and is not in the range
883 * of pages statically defined as 'unsaveable', and it isn't a part of
884 * a free chunk of pages.
887 static struct page
*saveable_page(unsigned long pfn
)
894 page
= pfn_to_page(pfn
);
896 BUG_ON(PageHighMem(page
));
898 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
))
901 if (PageReserved(page
) && pfn_is_nosave(pfn
))
908 * count_data_pages - compute the total number of saveable non-highmem
912 unsigned int count_data_pages(void)
915 unsigned long pfn
, max_zone_pfn
;
918 for_each_zone(zone
) {
919 if (is_highmem(zone
))
922 mark_free_pages(zone
);
923 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
924 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
925 if(saveable_page(pfn
))
931 /* This is needed, because copy_page and memcpy are not usable for copying
934 static inline void do_copy_page(long *dst
, long *src
)
938 for (n
= PAGE_SIZE
/ sizeof(long); n
; n
--)
942 #ifdef CONFIG_HIGHMEM
943 static inline struct page
*
944 page_is_saveable(struct zone
*zone
, unsigned long pfn
)
946 return is_highmem(zone
) ?
947 saveable_highmem_page(pfn
) : saveable_page(pfn
);
951 copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
953 struct page
*s_page
, *d_page
;
956 s_page
= pfn_to_page(src_pfn
);
957 d_page
= pfn_to_page(dst_pfn
);
958 if (PageHighMem(s_page
)) {
959 src
= kmap_atomic(s_page
, KM_USER0
);
960 dst
= kmap_atomic(d_page
, KM_USER1
);
961 do_copy_page(dst
, src
);
962 kunmap_atomic(src
, KM_USER0
);
963 kunmap_atomic(dst
, KM_USER1
);
965 src
= page_address(s_page
);
966 if (PageHighMem(d_page
)) {
967 /* Page pointed to by src may contain some kernel
968 * data modified by kmap_atomic()
970 do_copy_page(buffer
, src
);
971 dst
= kmap_atomic(pfn_to_page(dst_pfn
), KM_USER0
);
972 memcpy(dst
, buffer
, PAGE_SIZE
);
973 kunmap_atomic(dst
, KM_USER0
);
975 dst
= page_address(d_page
);
976 do_copy_page(dst
, src
);
981 #define page_is_saveable(zone, pfn) saveable_page(pfn)
984 copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
986 do_copy_page(page_address(pfn_to_page(dst_pfn
)),
987 page_address(pfn_to_page(src_pfn
)));
989 #endif /* CONFIG_HIGHMEM */
992 copy_data_pages(struct memory_bitmap
*copy_bm
, struct memory_bitmap
*orig_bm
)
997 for_each_zone(zone
) {
998 unsigned long max_zone_pfn
;
1000 mark_free_pages(zone
);
1001 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1002 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1003 if (page_is_saveable(zone
, pfn
))
1004 memory_bm_set_bit(orig_bm
, pfn
);
1006 memory_bm_position_reset(orig_bm
);
1007 memory_bm_position_reset(copy_bm
);
1009 pfn
= memory_bm_next_pfn(orig_bm
);
1010 if (unlikely(pfn
== BM_END_OF_MAP
))
1012 copy_data_page(memory_bm_next_pfn(copy_bm
), pfn
);
1016 /* Total number of image pages */
1017 static unsigned int nr_copy_pages
;
1018 /* Number of pages needed for saving the original pfns of the image pages */
1019 static unsigned int nr_meta_pages
;
1022 * swsusp_free - free pages allocated for the suspend.
1024 * Suspend pages are alocated before the atomic copy is made, so we
1025 * need to release them after the resume.
1028 void swsusp_free(void)
1031 unsigned long pfn
, max_zone_pfn
;
1033 for_each_zone(zone
) {
1034 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1035 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1036 if (pfn_valid(pfn
)) {
1037 struct page
*page
= pfn_to_page(pfn
);
1039 if (swsusp_page_is_forbidden(page
) &&
1040 swsusp_page_is_free(page
)) {
1041 swsusp_unset_page_forbidden(page
);
1042 swsusp_unset_page_free(page
);
1049 restore_pblist
= NULL
;
1053 #ifdef CONFIG_HIGHMEM
1055 * count_pages_for_highmem - compute the number of non-highmem pages
1056 * that will be necessary for creating copies of highmem pages.
1059 static unsigned int count_pages_for_highmem(unsigned int nr_highmem
)
1061 unsigned int free_highmem
= count_free_highmem_pages();
1063 if (free_highmem
>= nr_highmem
)
1066 nr_highmem
-= free_highmem
;
1072 count_pages_for_highmem(unsigned int nr_highmem
) { return 0; }
1073 #endif /* CONFIG_HIGHMEM */
1076 * enough_free_mem - Make sure we have enough free memory for the
1080 static int enough_free_mem(unsigned int nr_pages
, unsigned int nr_highmem
)
1083 unsigned int free
= 0, meta
= 0;
1085 for_each_zone(zone
) {
1086 meta
+= snapshot_additional_pages(zone
);
1087 if (!is_highmem(zone
))
1088 free
+= zone_page_state(zone
, NR_FREE_PAGES
);
1091 nr_pages
+= count_pages_for_highmem(nr_highmem
);
1092 pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
1093 nr_pages
, PAGES_FOR_IO
, meta
, free
);
1095 return free
> nr_pages
+ PAGES_FOR_IO
+ meta
;
1098 #ifdef CONFIG_HIGHMEM
1100 * get_highmem_buffer - if there are some highmem pages in the suspend
1101 * image, we may need the buffer to copy them and/or load their data.
1104 static inline int get_highmem_buffer(int safe_needed
)
1106 buffer
= get_image_page(GFP_ATOMIC
| __GFP_COLD
, safe_needed
);
1107 return buffer
? 0 : -ENOMEM
;
1111 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1112 * Try to allocate as many pages as needed, but if the number of free
1113 * highmem pages is lesser than that, allocate them all.
1116 static inline unsigned int
1117 alloc_highmem_image_pages(struct memory_bitmap
*bm
, unsigned int nr_highmem
)
1119 unsigned int to_alloc
= count_free_highmem_pages();
1121 if (to_alloc
> nr_highmem
)
1122 to_alloc
= nr_highmem
;
1124 nr_highmem
-= to_alloc
;
1125 while (to_alloc
-- > 0) {
1128 page
= alloc_image_page(__GFP_HIGHMEM
);
1129 memory_bm_set_bit(bm
, page_to_pfn(page
));
1134 static inline int get_highmem_buffer(int safe_needed
) { return 0; }
1136 static inline unsigned int
1137 alloc_highmem_image_pages(struct memory_bitmap
*bm
, unsigned int n
) { return 0; }
1138 #endif /* CONFIG_HIGHMEM */
1141 * swsusp_alloc - allocate memory for the suspend image
1143 * We first try to allocate as many highmem pages as there are
1144 * saveable highmem pages in the system. If that fails, we allocate
1145 * non-highmem pages for the copies of the remaining highmem ones.
1147 * In this approach it is likely that the copies of highmem pages will
1148 * also be located in the high memory, because of the way in which
1149 * copy_data_pages() works.
1153 swsusp_alloc(struct memory_bitmap
*orig_bm
, struct memory_bitmap
*copy_bm
,
1154 unsigned int nr_pages
, unsigned int nr_highmem
)
1158 error
= memory_bm_create(orig_bm
, GFP_ATOMIC
| __GFP_COLD
, PG_ANY
);
1162 error
= memory_bm_create(copy_bm
, GFP_ATOMIC
| __GFP_COLD
, PG_ANY
);
1166 if (nr_highmem
> 0) {
1167 error
= get_highmem_buffer(PG_ANY
);
1171 nr_pages
+= alloc_highmem_image_pages(copy_bm
, nr_highmem
);
1173 while (nr_pages
-- > 0) {
1174 struct page
*page
= alloc_image_page(GFP_ATOMIC
| __GFP_COLD
);
1179 memory_bm_set_bit(copy_bm
, page_to_pfn(page
));
1188 /* Memory bitmap used for marking saveable pages (during suspend) or the
1189 * suspend image pages (during resume)
1191 static struct memory_bitmap orig_bm
;
1192 /* Memory bitmap used on suspend for marking allocated pages that will contain
1193 * the copies of saveable pages. During resume it is initially used for
1194 * marking the suspend image pages, but then its set bits are duplicated in
1195 * @orig_bm and it is released. Next, on systems with high memory, it may be
1196 * used for marking "safe" highmem pages, but it has to be reinitialized for
1199 static struct memory_bitmap copy_bm
;
1201 asmlinkage
int swsusp_save(void)
1203 unsigned int nr_pages
, nr_highmem
;
1205 printk("swsusp: critical section: \n");
1207 drain_local_pages();
1208 nr_pages
= count_data_pages();
1209 nr_highmem
= count_highmem_pages();
1210 printk("swsusp: Need to copy %u pages\n", nr_pages
+ nr_highmem
);
1212 if (!enough_free_mem(nr_pages
, nr_highmem
)) {
1213 printk(KERN_ERR
"swsusp: Not enough free memory\n");
1217 if (swsusp_alloc(&orig_bm
, ©_bm
, nr_pages
, nr_highmem
)) {
1218 printk(KERN_ERR
"swsusp: Memory allocation failed\n");
1222 /* During allocating of suspend pagedir, new cold pages may appear.
1225 drain_local_pages();
1226 copy_data_pages(©_bm
, &orig_bm
);
1229 * End of critical section. From now on, we can write to memory,
1230 * but we should not touch disk. This specially means we must _not_
1231 * touch swap space! Except we must write out our image of course.
1234 nr_pages
+= nr_highmem
;
1235 nr_copy_pages
= nr_pages
;
1236 nr_meta_pages
= DIV_ROUND_UP(nr_pages
* sizeof(long), PAGE_SIZE
);
1238 printk("swsusp: critical section: done (%d pages copied)\n", nr_pages
);
1243 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
1244 static int init_header_complete(struct swsusp_info
*info
)
1246 memcpy(&info
->uts
, init_utsname(), sizeof(struct new_utsname
));
1247 info
->version_code
= LINUX_VERSION_CODE
;
1251 static char *check_image_kernel(struct swsusp_info
*info
)
1253 if (info
->version_code
!= LINUX_VERSION_CODE
)
1254 return "kernel version";
1255 if (strcmp(info
->uts
.sysname
,init_utsname()->sysname
))
1256 return "system type";
1257 if (strcmp(info
->uts
.release
,init_utsname()->release
))
1258 return "kernel release";
1259 if (strcmp(info
->uts
.version
,init_utsname()->version
))
1261 if (strcmp(info
->uts
.machine
,init_utsname()->machine
))
1265 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1267 static int init_header(struct swsusp_info
*info
)
1269 memset(info
, 0, sizeof(struct swsusp_info
));
1270 info
->num_physpages
= num_physpages
;
1271 info
->image_pages
= nr_copy_pages
;
1272 info
->pages
= nr_copy_pages
+ nr_meta_pages
+ 1;
1273 info
->size
= info
->pages
;
1274 info
->size
<<= PAGE_SHIFT
;
1275 return init_header_complete(info
);
1279 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1280 * are stored in the array @buf[] (1 page at a time)
1284 pack_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
1288 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
1289 buf
[j
] = memory_bm_next_pfn(bm
);
1290 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
1296 * snapshot_read_next - used for reading the system memory snapshot.
1298 * On the first call to it @handle should point to a zeroed
1299 * snapshot_handle structure. The structure gets updated and a pointer
1300 * to it should be passed to this function every next time.
1302 * The @count parameter should contain the number of bytes the caller
1303 * wants to read from the snapshot. It must not be zero.
1305 * On success the function returns a positive number. Then, the caller
1306 * is allowed to read up to the returned number of bytes from the memory
1307 * location computed by the data_of() macro. The number returned
1308 * may be smaller than @count, but this only happens if the read would
1309 * cross a page boundary otherwise.
1311 * The function returns 0 to indicate the end of data stream condition,
1312 * and a negative number is returned on error. In such cases the
1313 * structure pointed to by @handle is not updated and should not be used
1317 int snapshot_read_next(struct snapshot_handle
*handle
, size_t count
)
1319 if (handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
1323 /* This makes the buffer be freed by swsusp_free() */
1324 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
1328 if (!handle
->offset
) {
1331 error
= init_header((struct swsusp_info
*)buffer
);
1334 handle
->buffer
= buffer
;
1335 memory_bm_position_reset(&orig_bm
);
1336 memory_bm_position_reset(©_bm
);
1338 if (handle
->prev
< handle
->cur
) {
1339 if (handle
->cur
<= nr_meta_pages
) {
1340 memset(buffer
, 0, PAGE_SIZE
);
1341 pack_pfns(buffer
, &orig_bm
);
1345 page
= pfn_to_page(memory_bm_next_pfn(©_bm
));
1346 if (PageHighMem(page
)) {
1347 /* Highmem pages are copied to the buffer,
1348 * because we can't return with a kmapped
1349 * highmem page (we may not be called again).
1353 kaddr
= kmap_atomic(page
, KM_USER0
);
1354 memcpy(buffer
, kaddr
, PAGE_SIZE
);
1355 kunmap_atomic(kaddr
, KM_USER0
);
1356 handle
->buffer
= buffer
;
1358 handle
->buffer
= page_address(page
);
1361 handle
->prev
= handle
->cur
;
1363 handle
->buf_offset
= handle
->cur_offset
;
1364 if (handle
->cur_offset
+ count
>= PAGE_SIZE
) {
1365 count
= PAGE_SIZE
- handle
->cur_offset
;
1366 handle
->cur_offset
= 0;
1369 handle
->cur_offset
+= count
;
1371 handle
->offset
+= count
;
1376 * mark_unsafe_pages - mark the pages that cannot be used for storing
1377 * the image during resume, because they conflict with the pages that
1378 * had been used before suspend
1381 static int mark_unsafe_pages(struct memory_bitmap
*bm
)
1384 unsigned long pfn
, max_zone_pfn
;
1386 /* Clear page flags */
1387 for_each_zone(zone
) {
1388 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1389 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1391 swsusp_unset_page_free(pfn_to_page(pfn
));
1394 /* Mark pages that correspond to the "original" pfns as "unsafe" */
1395 memory_bm_position_reset(bm
);
1397 pfn
= memory_bm_next_pfn(bm
);
1398 if (likely(pfn
!= BM_END_OF_MAP
)) {
1399 if (likely(pfn_valid(pfn
)))
1400 swsusp_set_page_free(pfn_to_page(pfn
));
1404 } while (pfn
!= BM_END_OF_MAP
);
1406 allocated_unsafe_pages
= 0;
1412 duplicate_memory_bitmap(struct memory_bitmap
*dst
, struct memory_bitmap
*src
)
1416 memory_bm_position_reset(src
);
1417 pfn
= memory_bm_next_pfn(src
);
1418 while (pfn
!= BM_END_OF_MAP
) {
1419 memory_bm_set_bit(dst
, pfn
);
1420 pfn
= memory_bm_next_pfn(src
);
1424 static int check_header(struct swsusp_info
*info
)
1428 reason
= check_image_kernel(info
);
1429 if (!reason
&& info
->num_physpages
!= num_physpages
)
1430 reason
= "memory size";
1432 printk(KERN_ERR
"swsusp: Resume mismatch: %s\n", reason
);
1439 * load header - check the image header and copy data from it
1443 load_header(struct swsusp_info
*info
)
1447 restore_pblist
= NULL
;
1448 error
= check_header(info
);
1450 nr_copy_pages
= info
->image_pages
;
1451 nr_meta_pages
= info
->pages
- info
->image_pages
- 1;
1457 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1458 * the corresponding bit in the memory bitmap @bm
1462 unpack_orig_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
1466 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
1467 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
1470 memory_bm_set_bit(bm
, buf
[j
]);
1474 /* List of "safe" pages that may be used to store data loaded from the suspend
1477 static struct linked_page
*safe_pages_list
;
1479 #ifdef CONFIG_HIGHMEM
1480 /* struct highmem_pbe is used for creating the list of highmem pages that
1481 * should be restored atomically during the resume from disk, because the page
1482 * frames they have occupied before the suspend are in use.
1484 struct highmem_pbe
{
1485 struct page
*copy_page
; /* data is here now */
1486 struct page
*orig_page
; /* data was here before the suspend */
1487 struct highmem_pbe
*next
;
1490 /* List of highmem PBEs needed for restoring the highmem pages that were
1491 * allocated before the suspend and included in the suspend image, but have
1492 * also been allocated by the "resume" kernel, so their contents cannot be
1493 * written directly to their "original" page frames.
1495 static struct highmem_pbe
*highmem_pblist
;
1498 * count_highmem_image_pages - compute the number of highmem pages in the
1499 * suspend image. The bits in the memory bitmap @bm that correspond to the
1500 * image pages are assumed to be set.
1503 static unsigned int count_highmem_image_pages(struct memory_bitmap
*bm
)
1506 unsigned int cnt
= 0;
1508 memory_bm_position_reset(bm
);
1509 pfn
= memory_bm_next_pfn(bm
);
1510 while (pfn
!= BM_END_OF_MAP
) {
1511 if (PageHighMem(pfn_to_page(pfn
)))
1514 pfn
= memory_bm_next_pfn(bm
);
1520 * prepare_highmem_image - try to allocate as many highmem pages as
1521 * there are highmem image pages (@nr_highmem_p points to the variable
1522 * containing the number of highmem image pages). The pages that are
1523 * "safe" (ie. will not be overwritten when the suspend image is
1524 * restored) have the corresponding bits set in @bm (it must be
1527 * NOTE: This function should not be called if there are no highmem
1531 static unsigned int safe_highmem_pages
;
1533 static struct memory_bitmap
*safe_highmem_bm
;
1536 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
1538 unsigned int to_alloc
;
1540 if (memory_bm_create(bm
, GFP_ATOMIC
, PG_SAFE
))
1543 if (get_highmem_buffer(PG_SAFE
))
1546 to_alloc
= count_free_highmem_pages();
1547 if (to_alloc
> *nr_highmem_p
)
1548 to_alloc
= *nr_highmem_p
;
1550 *nr_highmem_p
= to_alloc
;
1552 safe_highmem_pages
= 0;
1553 while (to_alloc
-- > 0) {
1556 page
= alloc_page(__GFP_HIGHMEM
);
1557 if (!swsusp_page_is_free(page
)) {
1558 /* The page is "safe", set its bit the bitmap */
1559 memory_bm_set_bit(bm
, page_to_pfn(page
));
1560 safe_highmem_pages
++;
1562 /* Mark the page as allocated */
1563 swsusp_set_page_forbidden(page
);
1564 swsusp_set_page_free(page
);
1566 memory_bm_position_reset(bm
);
1567 safe_highmem_bm
= bm
;
1572 * get_highmem_page_buffer - for given highmem image page find the buffer
1573 * that suspend_write_next() should set for its caller to write to.
1575 * If the page is to be saved to its "original" page frame or a copy of
1576 * the page is to be made in the highmem, @buffer is returned. Otherwise,
1577 * the copy of the page is to be made in normal memory, so the address of
1578 * the copy is returned.
1580 * If @buffer is returned, the caller of suspend_write_next() will write
1581 * the page's contents to @buffer, so they will have to be copied to the
1582 * right location on the next call to suspend_write_next() and it is done
1583 * with the help of copy_last_highmem_page(). For this purpose, if
1584 * @buffer is returned, @last_highmem page is set to the page to which
1585 * the data will have to be copied from @buffer.
1588 static struct page
*last_highmem_page
;
1591 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
1593 struct highmem_pbe
*pbe
;
1596 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
)) {
1597 /* We have allocated the "original" page frame and we can
1598 * use it directly to store the loaded page.
1600 last_highmem_page
= page
;
1603 /* The "original" page frame has not been allocated and we have to
1604 * use a "safe" page frame to store the loaded page.
1606 pbe
= chain_alloc(ca
, sizeof(struct highmem_pbe
));
1611 pbe
->orig_page
= page
;
1612 if (safe_highmem_pages
> 0) {
1615 /* Copy of the page will be stored in high memory */
1617 tmp
= pfn_to_page(memory_bm_next_pfn(safe_highmem_bm
));
1618 safe_highmem_pages
--;
1619 last_highmem_page
= tmp
;
1620 pbe
->copy_page
= tmp
;
1622 /* Copy of the page will be stored in normal memory */
1623 kaddr
= safe_pages_list
;
1624 safe_pages_list
= safe_pages_list
->next
;
1625 pbe
->copy_page
= virt_to_page(kaddr
);
1627 pbe
->next
= highmem_pblist
;
1628 highmem_pblist
= pbe
;
1633 * copy_last_highmem_page - copy the contents of a highmem image from
1634 * @buffer, where the caller of snapshot_write_next() has place them,
1635 * to the right location represented by @last_highmem_page .
1638 static void copy_last_highmem_page(void)
1640 if (last_highmem_page
) {
1643 dst
= kmap_atomic(last_highmem_page
, KM_USER0
);
1644 memcpy(dst
, buffer
, PAGE_SIZE
);
1645 kunmap_atomic(dst
, KM_USER0
);
1646 last_highmem_page
= NULL
;
1650 static inline int last_highmem_page_copied(void)
1652 return !last_highmem_page
;
1655 static inline void free_highmem_data(void)
1657 if (safe_highmem_bm
)
1658 memory_bm_free(safe_highmem_bm
, PG_UNSAFE_CLEAR
);
1661 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
1664 static inline int get_safe_write_buffer(void) { return 0; }
1667 count_highmem_image_pages(struct memory_bitmap
*bm
) { return 0; }
1670 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
1675 static inline void *
1676 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
1681 static inline void copy_last_highmem_page(void) {}
1682 static inline int last_highmem_page_copied(void) { return 1; }
1683 static inline void free_highmem_data(void) {}
1684 #endif /* CONFIG_HIGHMEM */
1687 * prepare_image - use the memory bitmap @bm to mark the pages that will
1688 * be overwritten in the process of restoring the system memory state
1689 * from the suspend image ("unsafe" pages) and allocate memory for the
1692 * The idea is to allocate a new memory bitmap first and then allocate
1693 * as many pages as needed for the image data, but not to assign these
1694 * pages to specific tasks initially. Instead, we just mark them as
1695 * allocated and create a lists of "safe" pages that will be used
1696 * later. On systems with high memory a list of "safe" highmem pages is
1700 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
1703 prepare_image(struct memory_bitmap
*new_bm
, struct memory_bitmap
*bm
)
1705 unsigned int nr_pages
, nr_highmem
;
1706 struct linked_page
*sp_list
, *lp
;
1709 /* If there is no highmem, the buffer will not be necessary */
1710 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
1713 nr_highmem
= count_highmem_image_pages(bm
);
1714 error
= mark_unsafe_pages(bm
);
1718 error
= memory_bm_create(new_bm
, GFP_ATOMIC
, PG_SAFE
);
1722 duplicate_memory_bitmap(new_bm
, bm
);
1723 memory_bm_free(bm
, PG_UNSAFE_KEEP
);
1724 if (nr_highmem
> 0) {
1725 error
= prepare_highmem_image(bm
, &nr_highmem
);
1729 /* Reserve some safe pages for potential later use.
1731 * NOTE: This way we make sure there will be enough safe pages for the
1732 * chain_alloc() in get_buffer(). It is a bit wasteful, but
1733 * nr_copy_pages cannot be greater than 50% of the memory anyway.
1736 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
1737 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
1738 nr_pages
= DIV_ROUND_UP(nr_pages
, PBES_PER_LINKED_PAGE
);
1739 while (nr_pages
> 0) {
1740 lp
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
1749 /* Preallocate memory for the image */
1750 safe_pages_list
= NULL
;
1751 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
1752 while (nr_pages
> 0) {
1753 lp
= (struct linked_page
*)get_zeroed_page(GFP_ATOMIC
);
1758 if (!swsusp_page_is_free(virt_to_page(lp
))) {
1759 /* The page is "safe", add it to the list */
1760 lp
->next
= safe_pages_list
;
1761 safe_pages_list
= lp
;
1763 /* Mark the page as allocated */
1764 swsusp_set_page_forbidden(virt_to_page(lp
));
1765 swsusp_set_page_free(virt_to_page(lp
));
1768 /* Free the reserved safe pages so that chain_alloc() can use them */
1771 free_image_page(sp_list
, PG_UNSAFE_CLEAR
);
1782 * get_buffer - compute the address that snapshot_write_next() should
1783 * set for its caller to write to.
1786 static void *get_buffer(struct memory_bitmap
*bm
, struct chain_allocator
*ca
)
1789 struct page
*page
= pfn_to_page(memory_bm_next_pfn(bm
));
1791 if (PageHighMem(page
))
1792 return get_highmem_page_buffer(page
, ca
);
1794 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
))
1795 /* We have allocated the "original" page frame and we can
1796 * use it directly to store the loaded page.
1798 return page_address(page
);
1800 /* The "original" page frame has not been allocated and we have to
1801 * use a "safe" page frame to store the loaded page.
1803 pbe
= chain_alloc(ca
, sizeof(struct pbe
));
1808 pbe
->orig_address
= page_address(page
);
1809 pbe
->address
= safe_pages_list
;
1810 safe_pages_list
= safe_pages_list
->next
;
1811 pbe
->next
= restore_pblist
;
1812 restore_pblist
= pbe
;
1813 return pbe
->address
;
1817 * snapshot_write_next - used for writing the system memory snapshot.
1819 * On the first call to it @handle should point to a zeroed
1820 * snapshot_handle structure. The structure gets updated and a pointer
1821 * to it should be passed to this function every next time.
1823 * The @count parameter should contain the number of bytes the caller
1824 * wants to write to the image. It must not be zero.
1826 * On success the function returns a positive number. Then, the caller
1827 * is allowed to write up to the returned number of bytes to the memory
1828 * location computed by the data_of() macro. The number returned
1829 * may be smaller than @count, but this only happens if the write would
1830 * cross a page boundary otherwise.
1832 * The function returns 0 to indicate the "end of file" condition,
1833 * and a negative number is returned on error. In such cases the
1834 * structure pointed to by @handle is not updated and should not be used
1838 int snapshot_write_next(struct snapshot_handle
*handle
, size_t count
)
1840 static struct chain_allocator ca
;
1843 /* Check if we have already loaded the entire image */
1844 if (handle
->prev
&& handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
1847 if (handle
->offset
== 0) {
1849 /* This makes the buffer be freed by swsusp_free() */
1850 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
1855 handle
->buffer
= buffer
;
1857 handle
->sync_read
= 1;
1858 if (handle
->prev
< handle
->cur
) {
1859 if (handle
->prev
== 0) {
1860 error
= load_header(buffer
);
1864 error
= memory_bm_create(©_bm
, GFP_ATOMIC
, PG_ANY
);
1868 } else if (handle
->prev
<= nr_meta_pages
) {
1869 unpack_orig_pfns(buffer
, ©_bm
);
1870 if (handle
->prev
== nr_meta_pages
) {
1871 error
= prepare_image(&orig_bm
, ©_bm
);
1875 chain_init(&ca
, GFP_ATOMIC
, PG_SAFE
);
1876 memory_bm_position_reset(&orig_bm
);
1877 restore_pblist
= NULL
;
1878 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
1879 handle
->sync_read
= 0;
1880 if (!handle
->buffer
)
1884 copy_last_highmem_page();
1885 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
1886 if (handle
->buffer
!= buffer
)
1887 handle
->sync_read
= 0;
1889 handle
->prev
= handle
->cur
;
1891 handle
->buf_offset
= handle
->cur_offset
;
1892 if (handle
->cur_offset
+ count
>= PAGE_SIZE
) {
1893 count
= PAGE_SIZE
- handle
->cur_offset
;
1894 handle
->cur_offset
= 0;
1897 handle
->cur_offset
+= count
;
1899 handle
->offset
+= count
;
1904 * snapshot_write_finalize - must be called after the last call to
1905 * snapshot_write_next() in case the last page in the image happens
1906 * to be a highmem page and its contents should be stored in the
1907 * highmem. Additionally, it releases the memory that will not be
1911 void snapshot_write_finalize(struct snapshot_handle
*handle
)
1913 copy_last_highmem_page();
1914 /* Free only if we have loaded the image entirely */
1915 if (handle
->prev
&& handle
->cur
> nr_meta_pages
+ nr_copy_pages
) {
1916 memory_bm_free(&orig_bm
, PG_UNSAFE_CLEAR
);
1917 free_highmem_data();
1921 int snapshot_image_loaded(struct snapshot_handle
*handle
)
1923 return !(!nr_copy_pages
|| !last_highmem_page_copied() ||
1924 handle
->cur
<= nr_meta_pages
+ nr_copy_pages
);
1927 #ifdef CONFIG_HIGHMEM
1928 /* Assumes that @buf is ready and points to a "safe" page */
1930 swap_two_pages_data(struct page
*p1
, struct page
*p2
, void *buf
)
1932 void *kaddr1
, *kaddr2
;
1934 kaddr1
= kmap_atomic(p1
, KM_USER0
);
1935 kaddr2
= kmap_atomic(p2
, KM_USER1
);
1936 memcpy(buf
, kaddr1
, PAGE_SIZE
);
1937 memcpy(kaddr1
, kaddr2
, PAGE_SIZE
);
1938 memcpy(kaddr2
, buf
, PAGE_SIZE
);
1939 kunmap_atomic(kaddr1
, KM_USER0
);
1940 kunmap_atomic(kaddr2
, KM_USER1
);
1944 * restore_highmem - for each highmem page that was allocated before
1945 * the suspend and included in the suspend image, and also has been
1946 * allocated by the "resume" kernel swap its current (ie. "before
1947 * resume") contents with the previous (ie. "before suspend") one.
1949 * If the resume eventually fails, we can call this function once
1950 * again and restore the "before resume" highmem state.
1953 int restore_highmem(void)
1955 struct highmem_pbe
*pbe
= highmem_pblist
;
1961 buf
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
1966 swap_two_pages_data(pbe
->copy_page
, pbe
->orig_page
, buf
);
1969 free_image_page(buf
, PG_UNSAFE_CLEAR
);
1972 #endif /* CONFIG_HIGHMEM */